Method to Produce Catalytically Active Nanocomposite Coatings
A nanocomposite coating and method of making and using the coating. The nanocomposite coating is disposed on a base material, such as a metal or ceramic; and the nanocomposite consists essentially of a matrix of an alloy selected from the group of Cu, Ni, Pd, Pt and Re which are catalytically active for cracking of carbon bonds in oils and greases and a grain structure selected from the group of borides, carbides and nitrides.
The United States Government claims certain rights in this invention pursuant to Contract No. W-31-109-ENG-38 between the United States Government and the University of Chicago and/or pursuant to DE-AC02-06CH11357 between the Untied States Government and UChicago Argonne, LLC representing Argonne National Laboratory.
FIELD OF THE INVENTIONThe present invention relates to coating materials and methods of manufacture thereof. More particularly the invention relates to catalytically active nanocomposite coatings and methods of manufacture to provide low friction surface layers for a variety of lubricant uses, such as for engines.
BACKGROUND OF THE INVENTIONCurrent engine oils and greases typically include additives to enhance lubrication properties. Such additives include, for example, the well known additive ZDDP and MoTDC. However, these additives are very harmful to effective operation of catalytic converters and other after treatment devices for engines using such additive containing lubricants. The result is incomplete and ineffective operation of such devices which causes environmental pollution. Consequently, there is a substantial need to eliminate use of such additives in lubricants while still providing excellent engine operation and wear resistance while avoiding environmental pollution.
SUMMARY OF THE INVENTIONCompositions of coatings and methods of manufacture are directed to nanocomposite coatings with high catalytic reactivity to provide excellent lubrication properties between materials sliding relative to one another. These coatings cause catalytic activity which cracks long chain hydrocarbon molecules in base lubricating oils and greases to form a slick and highly protective (high wear and scuff resistance) carbon based film for sliding surfaces. Analyses show the film is carbon based and are structurally similar to ultra-low friction carbon films such as are described in U.S. Pat. No. 6,548,173 which is incorporated by reference herein. The subject nanocomposite coatings are catalytically active metal alloys, including alloys of metals such as, for example, Cu, Ni, Pd, Pt and Re as the matrix and grains of transition metal and refractory metal nitrides, carbo-nitrides, carbides or borides. Various examples of preformed alloy compositions are described hereinafter. Such nanocomposite coatings provide excellent scuffing and wear resistance without need for the use of deleterious additives.
These and other objects, advantages, and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings.
The invention is directed to methods of preparation of catalytically active nanocomposite coatings. Rather than add lubricant additives, which have substantial deleterious effects, the method of the invention concerns depositing of catalytically active metal based films on engine or machine parts which are in contact and moving while in contact. Various catalytically active coatings are therefore deposited by any one of various conventional deposition methodologies, such as, PVD, CVD and ALD. Such selected hard/soft-phase nanocomposite coatings enable substantial improvement of scuff and wear resistance for engine or machinery with sliding contact.
In
In order to overcome the disadvantages of such additives, the engine or machine components can be coated at selected friction points, to provide a film which is a nanocomposite of catalytically active ingredients, generally including one or more of Cu, Ni, Pd, Pt and Re as a matrix and grains of a transition or refractory metal nitride, carbide, carbo-nitrides and borides. As shown in
In order to evaluate the nature of the coating, tests were performed on a metal test component as shown in
In
Diamond and graphite (graphite reference is for a disordered graphite in
This is an example of preparation of a nanocomposite coating of Mo—N—Cu done by Magnetron sputtering.
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- Process-ID:xxx
- Cathode 2: Mo
- Cathode 1: Mo—Cu (20% at. Cu)
The foregoing description of embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the present invention. The embodiments were chosen and described in order to explain the principles of the present invention and its practical application to enable one skilled in the art to utilize the present invention in various embodiments, and with various modifications, as are suited to the particular use contemplated.
Claims
1. A nanocomposite coating base layer consisting essentially of a matrix of an alloy selected from the group of Cu, Ni, Pd, Pt and Re and mixtures thereof and grains selected from the group of a boride, a carbide, a carbo-nitride and a nitride.
2. The nanocomposite coating as defined in claim 1 wherein the alloy is about 1% to 10% by weight for the matrix and the grains from about 90% to 99% by weight.
3. The nanocomposite coating as defined in claim 1 further including a carbon containing layer disposed on the nanocomposite coating and the carbon containing layer formed by disposing an oil on the nanocomposite coating and moving another metal layer against the nanocomposite base layer, thereby catalytically cracking molecules of the disposed oil to form the carbon containing layer.
4. The nanocomposite coating as defined in claim 1 wherein the grains consist essentially of transition metal carbides, nitrides, carbo-nitrides and borides.
5. The nanocomposite coating as defined in claim 1 wherein the grains consist essentially of refractory metal carbides, nitrides, carbo-nitrides and borides.
6. A method for lubricating materials in wear contact, comprising the steps of:
- providing a base material;
- disposing a nanocomposite coating on the base material, the nanocomposite consisting essentially of a microstructural matrix of a catalytically active alloy selected from the group of Cu, Ni, Pd, Pt and Re and mixtures thereof and grains embedded in the matrix with the grains selected from the group of borides, carbides, carbo-nitrides and nitrides;
- disposing an oil on the nanocomposite coating;
- contacting the nanocomposite coating with a layer on another surface and cracking carbon bonds of the oil to form a lubricant derived carbon film disposed between the coating and the layer, thereby lubricating the nanocomposite coating and underlying base material.
7. The method as defined in claim 6 wherein the alloy is about 1% to 10% by weight and the grains from about 90% to 99% by weight.
8. The method as defined in claim 6 wherein the base material is selected from the group of a metal and a ceramic.
9. The method as defined in claim 6 wherein the different material is selected from the group of a metal and a ceramic.
10. The method as defined in claim 6 wherein the base material comprises a steel based material.
11. The method as defined in claim 6 wherein the oil is essentially free of additives.
12. The method as defined in claim 6 where the carbon containing layer consists essentially of diamond like carbon.
13. The method as defined in claim 6 where the grains are selected from the group of transition metal carbides, carbo-nitrides, nitrides and borides.
14. The method as defined in claim 6 where the grains are selected from the group of refractory metal carbides, carbo-nitrides, nitrides and borides.
Type: Application
Filed: Sep 30, 2011
Publication Date: Apr 4, 2013
Patent Grant number: 9255238
Inventors: Ali Erdemir (Naperville, IL), Osman Levent Eryilmaz (Plainfield, IL), Mustafa Urgen (Istanbul), Kursat Kazmanli (Istanbul)
Application Number: 13/250,760
International Classification: C10M 103/02 (20060101); C10M 177/00 (20060101); B01J 27/24 (20060101); B01J 21/02 (20060101); B05D 3/10 (20060101); B01J 27/22 (20060101);